CBS threatens ABC over new reality show May 4, 2012, 4:28 PM EST By Tim MolloyTheWrap CBS's lawyers have threatened ABC that its upcoming summer reality series, "Glass House," is copying CBS's "Big Brother" in a way that constitutes "a classic case of copyright infringement."Saying that they will pursue "all available remedies if this course of action continues" (you'll recognize that as lawyer talk for "we'll sue"), the attorneys demanded a stop to ABC's plans.

ABC did not immediately respond to a request for comment.

The letter, from the law firm Gibson, Dunn & Crutcher LLP, comes just three days after ABC announced plans for "Glass House," which was slated to debut June 18. In its release about the show, ABC said it would feature "14 contestants [who] will live and compete for a quarter million dollars in a totally wired, state-of-the-art house, playing not just against each other, but also playing to win over the viewing audience each week."

CBS noted several similarities to "Big Brother," which features 12-14 people living in a wired, state-of-the-art house, competing to avoid eviction, with input from viewers at home. It also said "Glass House" is being led and staffed largely by "Big Brother" veterans, who have signed non-disclosure agreements barring them from revealing proprietary information or trade secrets.

To signal how serious they are about litigation, they also demanded that ABC maintain and preserve all documents, including texts and emails, about the creation of the show. If the matter goes to court, CBS's lawyers would try to show that ABC ripped off concepts from "Big Brother."